Improvement in glass-annealing furnaces



J. LOWERY.

GLASS ANNEALING FURNACE.

No. 188,745. Patented March 27,1877.

M Law 7 7 NPEIERS, FHDTGJJTNOGRAPHER. WASHINGTON, D Cv UNITED" STATESPATENT OFFIon JOHN LQWEBY, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TOEXUELSIOR FLINT GLASS COMPANY, OF SAME PLACE.

IMPROVEMENT IN GLASS-ANNEALING FURNACES.

Specification forming part of Letters Patent N 0'. 188,745, dated March27, 1877; application filed March 1, 1877'.

To all whom it may concern:

Be it known that-I, JOHN LOWERY, of Pittsburg, county of Allegheny,State of Pennsyl- Vania, have invented .or discovered a new and usefulImprovement in Glass-Annealing Ovens; and I do hereby declare thefollowing to be a full, clear, concise, and exact description thereof,reference being had to the accompanying drawing, making a part of thisspecification, in which-like letters indicating like parts- 4 Figure 1is a sectional perspective of my improved annealing-oven, and Fig. 2 isan outside perspective.

The annealing-ovens or leers heretofore in most common use for annealingglassware have consisted of a long trunk or chamber, with a furnace atone end for the supply of the requisite heat, and a stack at a pointmore or less distant from the other end to carryofl' the unabsorbed andwaste heat. An objection to this even is, that it is difficult toregulate the temperature at the hot end, so that the manufactured wareintroduced at that end shall be raised to the proper temperature, and nomore, the proper temperature being but little short of that at which theglass would become plastic, or so much so as no longer to retain itsshape; also, from the furnace end to the stack the temperature is too.nearly uniform, and from the stack on it is reduced too rapidly orabruptly to give the best results. In my improved oven 1 have thetemperature at all times under such perfect control that it may withsafety and accuracy be brought up to the maximum, and then reduced asrapidly or slowly, and in either case as uniformly, as may be desired.

In the drawing, A represents a fire-chamber, of any suitableconstruction, with gratebars a, ash-pit A and door A A fine, B, openedand closed by a damper, b, leads directly therefrom to the stack. Oneach side of this fire-chamber I make an oven, which consists of anouter case, D, preferably of brick-work, and an inner case or box, Dpreferably of heavy sheet or boiler-plate iron, though other materialmay be used, if preferred. The box D rests on two or more hearings orsupports, 0, and between these a series of dues, c, extend from thefire-chamber A along under the box D and at their outer ends they openinto the uptake-flue d, which connects with the top flue d, and thelatter with a diving-flue, d which latter opens into a flue, B, leadingto the stack, such flue being opened and closed by a damper, b. The boxD is constructed to receive a series of trays or racks, e, and on theseI place the pans containing the articles of glassware to be annealed.The bottom flues c are opened and closed by sliding registers O, orequivalent dampers. The box D is so built in its case D that the doors Dwill close it up air-tight, or practically so.

For the purpose of admitting external cold air, when desired, into theflues c d 01 W, and in regulated quantities, I make holes or openings.9, closed by stoppers, slides, or doors 8, at any desired points infront and rear, or at the ends, or both. The number, size, andarrangement of these may be varied at pleasure. A thermometer orpyrometer, or both, are to be connected with the interior of the box Dto guide the operator in regulating the temperature.

The boxes D are to be air-tight, (when closed,) or practically so, inorder that the glass may not be injuriously affected by any deleteriousgases, dust, or ashes carried over from the fire-chamber, nor by thechilling effect of external or cold air; and, also, that greateruniformity of temperature may be preserved throughout the box.

In practical use I intend that (in order to secure the best results)each box D shall have a capacity to contain and anneal the product ofone turn, or, generally speaking, of one set of hands doing what countswith them for one days work. The fire-chamber having been heated up, onebox, D is filled, the doors are closed, and luted if need be; thecold-air passages are closed, also the damper b; the proper register 0is opened, as also the damper b on that side.

The hot air, gases, and flame, playing along the flues c d d d, raisethe temperature of the box D as high as may be desired in theglassannealing operation-say from 500 to 600 Fahrenheit, more or less.When this is done, which will require, say, from two to three hours,more or less, the damper b is opened, 0 is closed, and the oven is leftto cool down by radiation; or one or more of the cold-air ports oropenings 3 are opened, and the draft of cold air along the flues c d (1ol is regulated by the damper b. In this way the operation of coolingmay be carried on with comparative rapidity, or slowly, as may bepreferred; and while this operation is going on the work of the nextturn may be charged into the other oven, and the ovens be thus usedalternately. Two or more ovens may be used for each single turn, if sopreferred, especially in works of large manufacturing capacity.

I claim herein as my invention- 1. The close box D with surroundingflues, in combination with a fire-chamber and ports, doors, dampers, orregisters suitably arranged for applying either hot air and gases alone,

or cold air alone, to the exterior of the box, the combination beingsubstantially as set forth.

2. A glass-annealing oven, consisting of a close box, D, outer case D,interposed flues c d d 11 and one or more cold-air ports, 8, incombination with fire-chamber A, flues B B, dampers b b, and register 0,substantially as set forth.

3. A fire-chamber, A, having an independent'smoke-flue, B, and damper b,in combination with a glass-annealing oven on each side of the same, andan independent system of flues or passages, regulated by registersleading from the fire-chamber around each annealin g-box, whereby theeffective heat of the firechamber can be directed onto either box, orcut ofl from both, at pleasure, the combination being substantially asset forth.

In testimony whereof I have hereunto set my hand.

Witnesses: JOHN LOWERY.

J. J. MCCORMICK, CLAUDIUS L. PARKER.

